Underground man-made objects, such as utility lines, cables and pipes (hereinafter “underground facilities”), are very susceptible to damage from excavation activities. Local and federal laws require that notification be given to owners of underground facilities in an area to be excavated before any excavation takes place. The owners of the underground facilities typically must locate and mark the location of any underground facilities.
The tasks of locating and marking underground facilities can be performed by either the underground facility owner or by third party contractors. A marking tool is typically used to mark the ground, pavement or other surfaces in order to provide a visual indication of the location of underground facilities. Paint is commonly used as the marker, and it is typically applied using a paint marking tool. The color of the paint is typically chosen based on the type of facility being marked (e.g., red for a power line). However, other types of markers, such as other types of liquids, flags and stakes are also used, and different visual or other characteristics of the marker are used for representing different types of underground facilities. For example, the color, shape or other characteristic of a flag marker can represent a particular type of underground facility (e.g., a square shaped flag can be used to mark a power line).
When paint is used as the marker, a worker marks the location of an underground facility using a paint marking tool to spray paint on the ground to mark the presence or absence of an underground facility. The paint marking tools typically used have a paint canister holder that is adapted to hold a single aerosol can of paint in an axial orientation with respect to the long axis of the aerosol can. The paint marking tool is typically designed to enable a user to walk or stand erect while dispensing the paint.
When an underground facility is located, the worker will load a paint can of the appropriate color for the underground facility being marked into the paint marking tool. When it is time to mark a different type of underground facility, the worker must change the paint can to one of the appropriate color for the new underground facility being marked.
Inaccurate marking of the underground facilities can result in physical damage to underground facilities, property damage, and/or personal injury during the excavation process that, in turn, can expose the underground facility owner or contractor to significant legal liability. When underground facilities are damaged and/or when property damage or personal injury results from hitting a underground facility during an excavation, the excavator may assert that the underground facility was not accurately marked by the entity that carried out the marking, while the entity that marked the underground facility will assert that the underground facility was properly marked. Proving whether the underground facility was properly marked can be difficult after the excavation, because in many cases the paint line used to mark the underground facility will have been disturbed or destroyed during the excavation process,